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| Titel |
Steam jacket dynamics in underground coal gasification |
| VerfasserIn |
Christopher Otto, Thomas Kempka |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250150111
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| Publikation (Nr.) |
 EGU/EGU2017-14539.pdf |
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| Zusammenfassung |
| Underground coal gasification (UCG) has the potential to increase the world-wide
hydrocarbon reserves by utilization of deposits not economically mineable by conventional
methods. In this context, UCG involves combusting coal in-situ to produce a high-calorific
synthesis gas, which can be applied for electricity generation or chemical feedstock
production. Apart from high economic potentials, in-situ combustion may cause
environmental impacts such as groundwater pollution by by-product leakage. In order to
prevent or significantly mitigate these potential environmental concerns, UCG reactors are
generally operated below hydrostatic pressure to limit the outflow of UCG process fluids into
overburden aquifers. This pressure difference effects groundwater inflow into the
reactor and prevents the escape of product gas. In the close reactor vicinity, fluid flow
determined by the evolving high reactor temperatures, resulting in the build-up of a steam
jacket.
Numerical modeling is one of the key components to study coupled processes in in-situ
combustion. We employed the thermo-hydraulic numerical simulator MUFITS
(BINMIXT module) to address the influence of reactor pressure dynamics as well as
hydro-geological coal and caprock parameters on water inflow and steam jacket
dynamics.
The US field trials Hanna and Hoe Creek (Wyoming) were applied for 3D model
validation in terms of water inflow matching, whereby the good agreement between our
modeling results and the field data indicates that our model reflects the hydrothermal physics
of the process. In summary, our validated model allows a fast prediction of the steam jacket
dynamics as well as water in- and outflows, required to avoid aquifer contamination during
the entire life cycle of in-situ combustion operations. |
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